What is quantum biology

The bold concepts of quantum biologyQubits in the head

Quantum physics challenges our imagination to the utmost: Particles can be in two places at the same time or have a ghostly connection with their fellows. Actually, these strange laws should only apply in the microcosm, in the world of atoms and molecules - so the common doctrine. But some experts assume that quantum effects are also central to life - in photosynthesis in leafy green, in the sense of direction of migratory birds or even for the thinking processes in our brain, which may function like a quantum computer.

Paradigm shift or pure researcher's imagination?

In order to test their theses, various research teams have now set up complex experiments. If they succeed, they are likely to result in a paradigm shift in biology and brain research - fundamental natural processes would run completely differently than expected. But the attempts are met with skepticism: Many experts consider them to be in vain and are convinced that quantum effects are far too weak and fleeting to play a significant role in life.

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Ulm University, an office in the Institute for Theoretical Physics.

"I am a professor. I have a job, nothing can happen to me. It is actually my duty to pursue something speculative and not just continue to follow the well-trodden path."

Martin Plenio is sitting in front of his computer. On the screen: a green-blue pattern, it trembles and wobbles around the edges, barely noticeable.

"You have to try to do something exciting new."

(picture alliance / dpa / Patrick Pleul) Quantum cosmos - the family of Schrödinger's cat The most prominent symbol of the absurd quantum world is Schrödinger's cat - a thought experiment in which the poor animal is both alive and dead. But now an international research team has been able to increase this curiosity even more.

The wobble on the screen would be the new: quantum effects. It is known that they rule atoms and elementary particles, i.e. the world of physics. Could they also shape life? The thesis polarizes.

"A lot of things were ridiculed at the beginning and turned out to be right in the end."

Pioneer Werner Heisenberg

June 1925. Werner Heisenberg, just 23 years old, is recovering from his hay fever on Heligoland. He achieved a scientific breakthrough in the seclusion of the island: He found the mathematical formulas of quantum mechanics - a paradigm shift in physics.

Werner Heisenberg - he developed the Heisenberg uncertainty relation and received the Nobel Prize in Physics in 1932. (picture alliance / Georg Goebel)

"Quantum physics comes into play when matter is described in the size range of atoms, molecules and below," explains Michael Thorwart, quantum physicist from the University of Hamburg. "Quantum physics describes properties and dynamic processes with special terms that are completely different from those used in classical physics. They often have no intuitive equivalent in classical physics."

Quantum physics also in living nature?

An atom can be a wave and a particle at the same time. Can be in two places at the same time, determined by chance. And can be connected to other quanta through a ghostly action at a distance. A confusing set of rules, non-illustrative, counter-intuitive, yet almost perfect.

(imago / Weiss) Quantum entanglement - strange rules of quantum physics
Physicists at TU Delft are confident: their experiment on quantum entanglement will end a discussion that has been going on for 80 years. She had toasted Albert Einstein. The Nobel Prize winner thought some quantum physics phenomena were too absurd to be true - but they actually are, say the Dutch researchers.

Soon after Heisenberg's stroke of genius, other quantum pioneers came up with a daring idea - above all Heisenberg's colleague Pascual Jordan. Michael Thorwart:

"As early as 1932 he postulated that the question of what brings living nature to life can be answered by the laws of quantum physics."

Jordan's hypothesis: Quantum physics not only shapes the world of the smallest particles, but also the behavior of biomolecules, the play material of life. This behavior then spreads to cells, organs - and finally to the whole body.

"He called it the amplifier theory. He even drew a connection between quantum physics and psychology."

Pascual Jordan (1902-1980) (University of Göttingen)

Crude theses frighten the professional world

Pascual Jordan was a member of the NSDAP, he sympathized with the Nazis. There his thesis met with some approval. Thorwart:

"He even formulated that the leader principle is a central principle of the biology of life and that every living cell has a control center as a dictatorial authority. Fortunately, such absurd approaches are history today."

Crude theses that ensured that experts would rather keep their hands off the underlying question: Can it be that quantum phenomena determine the elementary processes of life? Is biology really a quantum biology? Actually an impossibility. As a rule, quantum phenomena are extremely fragile and can only unfold where quantum particles are isolated from the outside world, for example in a vacuum.

Resurrection of a hypothesis

Still, some researchers have picked up the thread again. They suspect quantum effects behind the most varied of life processes - in photosynthesis in green leaves, in the sense of direction of migratory birds or in the human brain, which may function like a quantum computer. A technical article in the renowned specialist magazine NATURE marked the start 13 years ago.

2007. The Ulm physicist Martin Plenio is once again in a meeting.

"And someone said: Oh, there was this article, quantum computing happens in biology. I thought: Okay, it's definitely wrong."

"Wave-like dynamics" in photosynthesis

The article is from the group of chemist Graham Fleming in Berkeley, California. The team is experimenting with a still young measurement method - ultra-short laser flashes, with which extremely fast processes such as photosynthesis can be observed in super slow motion.

"This allowed you to take a close look at photosynthetic complexes. And at that time you found signals that oscillated. From this, you concluded that there must be wave-like dynamics. And wave-like dynamics always speak for quantum mechanical phenomena."

(imago / View Stock) Research project on artificial photosynthesis
Artificially simulating the process of photosynthesis - and doing it efficiently: If this succeeds, large quantities of hydrogen could be produced using solar energy. Researchers from Germany and the USA have come closer to this dream.

In plants, sunlight turns into chemical energy. The light releases electrical charges from the molecular compound in chlorophyll, the leaf green. These charges then move extremely quickly to other places in the molecule in order to provide the energy for the formation of carbohydrates there.

Light energy in harmony with vibrations

For decades, experts have been puzzling over why photosynthesis is so effective: How does nature manage to transport electrons so quickly that the energy can actually be used chemically? In 2007, Fleming and his team presented a new approach with their article: They want to have observed that quantum phenomena do not only show themselves at the first moment when the light hits the leafy green. But that the quantum behavior lasts much longer and thus also determines the subsequent processes: According to Fleming, the energy of the light particle runs coherently, quasi in synchronism through the molecular complex - a typical quantum behavior. Martin Plenio is fascinated and decides to enter the new branch of research - quantum biology.

"And then we discovered a lot. The basic statement is: Yes, in these photosynthetic complexes there is quantum coherence and quantum dynamics, and they play a role in transport.

The use of sunlight through photosynthesis is the basis for most of the biological processes on earth. (dpa / picture alliance / Arno Burgi)

Explanation for the efficiency of photosynthesis?

Figuratively speaking, the energy of the light particle can follow all possible paths simultaneously on its way through the molecular complex, instead of laboriously searching for the shortest one. But that doesn't seem to be all:

"In these transport processes and also later in charge separation, it is very important that the protein, i.e. the background on which this transport takes place, is not a rigid body that does not move at all. Rather, it fluctuates and, so to speak, oscillates itself."

And vibrates quantum-wise - indefinitely and randomly. Plenary:

"If we are on a dike and the wave arrives and the dike is high enough, then the wave doesn't go over it. But if the dike varies in height every now and then, and if it is just deeper, then it can Wave over it. "

Opposition from specialist colleagues

If the theory is correct, it would be clearer why photosynthesis is so effective. But there is a contradiction. Michael Thorwart also reads the NATURE paper by Graham Fleming in 2007, who claims to have observed quantum coherence in photosynthesis:

"Like everyone else, I was somewhat fascinated. At first I was convinced of the measurement results and also of the interpretation. It's a very tempting interpretation that could have led to spectacular results."

Thorwart is a theorist. His team tries to understand the new phenomenon with a computer simulation. The result is available in 2011. It's sobering:

"Our numerical calculations could not reproduce or explain the experiments. As a result, the editor of a journal in which we wanted to publish the results wrote to us: Your results do not agree with the experiment. Therefore, the theory must to be wrong."

Quantum effects only at the moment of light exposure?

But Thorwart believes in his model - and convinces an experimental team to repeat the tests from 2007 and to examine them critically. The result:

"We found out that the observed signals can be clearly assigned to ordinary oscillation coherences of the molecules. Ordinary oscillations occur everywhere in molecular physics and can be explained by the laws of classical physics."

According to this, quantum physics only plays a role in the very first moment, the moment the light is absorbed. As soon as the energy is transported over the molecular complex, the coherence breaks down and the quantum properties are lost in the expanses of the molecule. Thorwart:

"We now have a coherent picture and have adjusted the point of view from this 2007 paper in NATURE. In the meantime, this interpretation of the experiment, which was certainly initiated by us, has been accepted by the vast majority of scientists."

Tunnel processes in charge separation

Martin Plenio is not discouraged:

"When you do something new, there are always people who don't believe it and have a negative opinion. But you shouldn't let that influence you so much. As long as you don't look at it purely speculatively, but formulate it in good science in a measurably verifiable manner that's perfectly fine. "

Perhaps the quantum phenomena are not so central to the transport, but they are in a different step - the charge separation in the reaction center of the molecular complex.

"There really tunnel processes, i.e. quantum mechanical processes, take place there. That is actually the point, I think, where quantum mechanics really play a very essential role in making this charge separation efficient. So that it quickly becomes stable so that we can get the energy out of this electron can."

A new building for a new direction of research

A hypothesis that needs to be substantiated - through experiments in a brand new building.

"So, let's open up now."

The Center for Quantum Biosciences at the University of Ulm. Some offices have already been occupied, others are still empty, waiting for the last coat of paint.

"And then we go into the basement. There are the highly specific laboratories with which we want to carry out new experiments here. Here around the corner on the left."

Plenio heads for a room in which there is another, smaller room, the actual laboratory.

"A room in a room is called. A shell around it. And another room is built into this space shell so that you get more shielding. Electromagnetic fields, vibrations, temperature. Simply everything."

Room-in-room laboratory of the quantum biology project at Ulm University (Frank Grotelüschen / Dlf)

The outside world is perfectly shielded

There isn't much inside yet, the experimental equipment is still to come. They are placed on a 26-ton concrete block. When Plenio stands on it, there is a hiss: the block rests on air springs that absorb vibrations - footsteps, microquakes, shocks from the tram. Then the physicist points to the walls. They contain power coils that shield magnetic fields.

"The temperature is stabilized at 0.3 Kelvin. And it has a certain amount of sound absorption. When we close the door, it becomes very strangely quiet here, quieter than normal."

A laboratory perfectly shielded from the outside world. Because if the quantum effects really exist, they will be extremely weak.

"The more closely we want to examine nature, the more we have to suppress, eliminate, and balance out sources of interference. Only then will we see these very, very fine signals that we really want to look at."

Ten years to test the hypotheses

The tests are scheduled to start later this year. Plenio's vision:

"In ten years we should have clarified that these processes are taking place or not. If these processes actually turn out to be true, the big boost will of course go in the direction of: How can we use this to make better medicine? How can we use this to understand more detailed physiological processes and how we can influence them? That would be a very exciting time. "

Prof. Martin Plenio from Ulm University in his quantum biology laboratory (Frank Grotelüschen / Dlf)

The skeptical professionals are not the only ones with whom Martin Plenio has to grapple. Because there is another faction - quantum physicians and faith healers.

Difficult demarcation from esotericists

"Yes, of course that sometimes gives the field a bad name, because it is associated with this esotericism, where there is no scientific approach. The argument is simply like this: We do not understand the brain, we do not understand quantum mechanics - well, the two things must have something to do with each other! And that is a very, very bad approach. "

A quantum physics that creates a mystical connection between humans and the cosmos: For Martin Plenio this is pure nonsense:

"Every now and then I get emails or phone calls from people who are really excited that I'm doing quantum biology or quantum medicine or things like that. But then I try to explain to these people what the difference is in our approaches. But I think I usually don't really get away with it. "

The miracle of migratory bird navigation

University of Oldenburg. The biologist Henrik Mouritsen has been grappling with an old mystery for years.

"Once a migratory bird has flown to Africa and back, it has a precision of centimeters over 10,000 kilometers. GPS cannot do that. That's why it's amazing how a bird with a brain that weighs less than a gram is so precise can find the way to Africa. "

How do migratory birds manage to orientate themselves so precisely? The position of the sun and stars, concise landmarks - all of this helps the animals. But some birds also use something else - the earth's magnetic field.

"The magnetic field is mainly important for their compass when they are flying at night and have no solar information. We are mainly concerned with night migratory songbird species. Robin is one. Blackcap is another."

Magnetic crystal hypothesis "appears to be dead"

For a long time, experts believed that tiny magnetic crystals in the beak of animals were behind the magnetic sense.

"This hypothesis seems to be dead. There is a paper by a junior research group from Vienna. They showed that what was believed to be the crystals, they are actually macrophages."

So no internal compass, but immune cells. Apparently the animals' magnetic sense has to work differently. Henrik Mouritsen suspects an exotic quantum phenomenon: a protein called cryptochrome sits in the bird's eye. If a little light falls on it - that's enough from the stars - two electrons briefly become tiny bar magnets; a quantum effect.

Quantum effect with starlight?

Depending on the direction of the earth's magnetic field, the two electron magnets align themselves differently to one another. That affects a biochemical reaction. And this ultimately lets the bird recognize the direction of the compass. The first evidence suggests that there is something to it, says Mouritsen. This is how the magnetic sense disappears when the birds' eyes are covered:

"And then you also know that radio frequency fields have an influence on the magnetic compass ability of migratory birds - that can interfere. And that can be explained quantum mechanically, why that should be so."

The biologist Henrik Mouritsen heads the QuantumBirds project (Frank Grotelüschen / Dlf)

The "QuantumBirds" project

Only: The thesis has not yet been proven. To test them, Mouritsen started a project with a chemistry team from Oxford. The name: "QuantumBirds".

"Among other things, we successfully made and isolated this molecule, which we suspect, in bacterial cultures. And now you can see what happens directly from these molecules: How does this molecule behave when you change the magnetic field and when you light it seems and so on. "

There are also experiments with robins. They take place in a special building.

"There's only one building in the world. And that's here."

The walls are clad with aluminum, a shield against electromagnetic waves.

"So you can't use your mobile phone here, for example."

Magnetic field manipulations in the metal grid

In one of the rooms there is a metal grille, the size of a child's room. Inside, magnetic fields can be produced at the push of a button.

"Now you can see specifically how birds react to these magnetic stimuli. And we can be sure that something uncontrollable is not coming from the outside."

Henrik Mouritsen reaches for something that looks like an upside-down lampshade:

"It's a plastic funnel, where you put this scratch-sensitive paper along the edge in here. Then you can put protection on it so that the birds don't fly out. Then you let them sit in there for an hour. And then they showed during the lesson in which direction they wanted to fly that night. "

Scratch marks of the test birds show the preferred take-off direction

In autumn the scratch marks would usually point to the southwest, that is where the birds want to move. But in the aluminum frame, the earth's magnetic field can be switched off and replaced with an artificial one. And there are small jammers that send radio waves into the aluminum cage. It all comes down to these radio waves: They are supposed to directly influence the quantum compass in the bird's eye.

"If you turn the magnetic field, the place where the scratches are turns. And if you add radio frequency interference to that, it can mean that they scratched completely by accident and didn't hop in a certain direction."

In the coated plastic funnel you can see in which direction the birds have oriented (Frank Grotelüschen / Dlf)

Species protection with a reprogrammed quantum compass?

If the robins actually orient themselves using a quantum compass, the findings could at some point be useful for species protection. A quantum compass could be reprogrammed using radio waves and an artificial magnetic field in such a way that instead of flying into ruin, they head for a new region worth living in, says Mouritsen - and hopes for tangible results in five years:

"We see magnetic field effects, I can say that much. We hope to be able to show that there is a quantum mechanical sense in biology. If that is the case, it would be the first sense system in biology where it is necessary."

Lithium variants with astonishing differences

"I started looking at it seven years ago. I wanted to know why lithium is so effective in treating bipolar disorder. Friends and family of mine suffer from this mental illness. So I wanted to learn as much as possible about lithium . "

As such, Matthew Fisher at the University of California is working on solids and superconductors. But in 2013 he was concerned with a completely different question: Does it make a difference if you treat mental illnesses with two different types of lithium - the common lithium-7 and the rare lithium-6? Lithium-7 has one more neutron in the atomic nucleus than lithium-6. Chemically, both should be identical. However, in the 1980s, experiments on rats produced a surprising result:

"The effect of the two isotopes on rats was very different. I wanted to know why - should it be because the atomic nuclei have different spin? And that made me think in general about the role of nuclear spin in biology, not only with lithium. "

Magnetic Resonance Effects in the Brain?

Atomic nuclei have a spin, a kind of intrinsic twist. Figuratively speaking, they can either turn left or right - or both at the same time, a crazy consequence of quantum physics. The interesting thing: nuclear spins are comparatively stable and cannot be brought out of sync so quickly. This allows them to retain their quantum properties even in the restless environment of a cell. This gives Matthew Fisher an idea:

"Let's imagine that nuclear spins are involved in cognitive processes in the brain. In a kind of quantum process. I sometimes ask myself: Are we really quantum computers?"

Qubits in the head - the "QuantumBrain" project

An absurd sounding idea. Then we would literally have qubits in our head, the counterparts of the bits in an ordinary computer. To investigate the matter, Fisher starts a project called "Quantum Brain", financed by a private foundation. The central problem: what could the organic qubits consist of? Mathew Fisher:

"That can only be the phosphorus atom. Its nuclear spin is very well shielded from the outside world. And further considerations led to the fact that it must be a conglomerate of calcium and phosphorus."

Mitochondria as biological quantum computers?

Only in these agglomerations of calcium and phosphate would the nuclear spins be so stable that they could function as computing units. But: where exactly should it be? With this question, physicist Fisher does not get any further at first. Until he gets support from Germany, from the Technical University of Munich. Here the biologist Tobias Fromme read an article on the subject of quantum biology - and pricked up his ears:

"There Matthew Fisher was listed with his hypothesis. And there was, for my taste, nonsense about where this calcium phosphate, in which nerve cells, is exchanged. I wrote Matthew Fisher an e-mail, told him, I think I am knows better, namely in mitochondria. This is how the contact came about. And over the months it has become a cooperation, so that I am now part of the Quantum Brain Project and am also financed by it. "

Tobias Fromme in the "Quantum Brain" laboratory at the Technical University of Munich (Frank Grotelüschen / Dlf)

In search of entangled phosphorus atoms

Mitochondria are tiny cell organelles that power the cell. Here there could be agglomerations of calcium phosphate that act as qubits. In order to function as tiny computing units, they would have to be interconnected - via the quantum mechanical process of entanglement, once ridiculed by Albert Einstein as a spooky long-range effect. Tobias Fromme searches for signs of this entanglement in his laboratory. Tobias Fromme:

"Mitochondria are constantly dividing and thereby distributing the calcium phosphate to different particles or even to different cells. So that these entangled phosphorus atoms can end up in different places in the body. And that's the interesting phenomenon."

Invisible baton for cell coordination?

Can two phosphorus atoms still have a quantum mechanical connection even if they have been distributed to different cells? To clarify this, Pious marks mitochondria and cells with different colors and observes their behavior with a microscope. He wants to get the cells to expel calcium. The calculation: if the cells were entangled, they could, as it were, communicate with each other via a secret channel and simultaneously release the calcium, directed by an invisible baton.

"If we ensure that certain groups of cells all contain entangled calcium phosphate, one would look to see whether this group would fire more synchronously, i.e. all after precisely three seconds, instead of spread over one, two or three seconds."

Mitochondria microscope in the laboratory of the "Quantum Brain" project (Frank Grotelüschen / Dlf)

Which would be at least a first indication that there is something to the matter. Fromme is hoping for the first results this year.

So far overlooked signal processing mechanism?

"Of course, many colleagues say: Until you put this evidence on the table for me, it's all just a bubble. We specifically want to see whether it is hot air or not. Because if we find the evidence, and you like it so unlikely Finding how you want is extremely important. That would open a door to a completely new field of research. You would have overlooked a signal processing mechanism in our cells that has always been there. "

(imago / INSADCO) How quantum theory explains the world anew After biologists thought for a long time that they could safely neglect the bizarre laws of the microcosm, the insight is now maturing that phenomena from the quantum world could provide them with answers to great open questions. In their book "The Quantum Beat of Life", Jim Al-Khalili and Johnjoe McFadden describe this paradigm shift.

Matthew Fisher: "It's not an easy path we've taken. The brain is complicated, quantum mechanics is complicated, and we just don't know what will come of our project."

Michael Thorwart from Hamburg: "Matthew Fisher is a very cautious scientist, a very serious scientist. He proceeds very carefully, very carefully. He describes his concepts as highly speculative at best. And what comes out of it is interesting."

Lots of open questions - and very shaky terrain

If Fisher is correct, it should raise questions: Do the qubits control our thinking? Are flashes of inspiration created by quantum fluctuations? And is free will formed from the random fluctuations of some calcium phosphate lumps? Speculations Matthew Fisher Doesn't Want To Know About:

"If you start to ask how this affects our consciousness, you are entering shaky terrain. We are more interested in something else, namely what influence quantum processes could have on sensory perception. Talking about consciousness is very speculative."

And the self-proclaimed quantum healers? Should the qubits actually exist in the head or elsewhere in the nervous system - would their methods be scientifically proven all of a sudden? Hardly likely. Because how these qubits are supposed to connect with those of other people or with the whole cosmos, neither Matthew Fisher nor any other serious researcher could explain. Fisher:

"When it comes to quantum healing, scientists are very skeptical. And, unfortunately, this skepticism is carried over to our research for some."